Ruined lives. Lost fortunes. Federal crimes. Scientology poses as a religion but is really a ruthless global scam -- and aiming for the mainstream.

By all appearances, Noah Lottick of Kingston, Pa., had been a normal, happy 24-year-old who was looking for his place in the world. On the day last June when his parents drove to New York City to claim his body, they were nearly catatonic with grief. The young Russian-studies scholar had jumped from a 10th-floor window of the Milford Plaza Hotel and bounced off the hood of a stretch limousine. When the police arrived, his fingers were still clutching $171 in cash, virtually the only money he hadn't yet turned over to the Church of Scientology, the self-help "philosophy" group he...